Rainer Klaus Wirth Castro (born 25 October 1982) is a Chilean footballer who plays for Deportes La Serena as a goalkeeper.
He joined the Universidad Católica football academy in 1994, making his full first team debut for Católica against Paysandu in April 2003. Wirth ever played with regularity at Católica, but in January 2006, was loaned to Deportes Temuco for gain more experience under the three posts, returning the same year in June as the first-choice goalkeeper of Católica for replace to José María Buljubasich, operated of his bening brain tumor.
In January 2007, Wirth moved to rival side Colo-Colo for an undisclosed fee and also the same month he traveled to England to try out with Premier League club Manchester City, was revealed that the Chilean played very well, but the club not find a keeper for the club. He made fifteen appearances for the club, including 2007 Copa Sudamericana and 2008 Copa Chile.
After a regular 2008 season in the most successful team of Chile, Wirth was loaned to the recently promoted team from the Primera B, Municipal Iquique. In the club of the II Region of Chile, he suffered a fourth–month injury and the keeper Rodrigo Naranjo finished replacing to Wirth as the first choice keeper of the club for best performance. The next season, he ended contract with Colo-Colo and joined to Unión Española, in where played with more regularity during the 2010 season. In December of the next year, he was sacked of the club after a very regular 2011 and was signed by Deportes La Serena for the 2012 season.
Rainer is also son of the Chilean national football team of the 1982 FIFA World Cup, Oscar Wirth, who also played for the big three of the Chilean football: Colo-Colo, Universidad Católica and Universidad de Chile. He currently also studies at the Finis Terrae University a vespertine business engineering career.